1. Field of the Invention
The present invention relates to a spirocyclopentaphenanthrenefluorene-based compound and an organoelectroluminescent device using the same, and more particularly, to a spirocyclopentaphenanthrenefluorene-based compound with blue light-emitting characteristics, and an organoelectroluminescent device including an organic film containing the same to increase the purity of color and luminous efficiency.
2. Description of the Related Art
Cambridge University has developed an organoelectroluminescent device using a polyphenylenevinylene (PPV) film. The PPV film, which is a conjugated polymer, is prepared by wet-coating PPV. After the PPV-based conjugated polymer was disclosed, Covion Co. developed a novel PPV-type polymer, which is soluble in an organic solvent and has good chemical stability and luminous efficiency. Dow Chemical Co. has developed an emission layer-forming material polyfluorene-based compound, which performs better than the PPV-type polymer. The polyfluorene-based compound has been regarded as a blue light-emitting polymer. However, color purity of the polyfluorene-based compound has not met a desired level due to an excimer, which is generated on the side chains of a polyfluorene structure (U.S. Pat. No. 5,900,327 entitled Polyfluorenes as materials for photoluminescence and electroluminescence to Pei, et al., and issued on May 4, 1999). Therefore, there is a need to develop a polyfluorene-based compound with high color purity.
In order to increase color purity characteristics of the polyfluorene, U.S. Pat. No. 5,621,131 entitled Conjugated polymers having spiro centers and their use as electroluminescence materials to Kreuder, et al. and issued on Apr. 15, 1997 disclosed a luminescent material containing polyspirofluorenes, and U.S. Pat. No. 5,763,636 entitled Polymers containing spiro atoms and methods of using the same as electroluminescence materials to Kreuder, et al. and issued on Jun. 9, 1998 and U.S. Pat. No. 5,859,211 entitled Conjugated polymers containing heterospiro atoms and their use as electroluminescence materials to Kreuder, et al. and issued on Jan. 12, 1999 disclosed luminescent materials having a spirobifluorene, or a spirofluorene containing a heteroatom.
However, organoelectroluminescent devices using luminescent materials developed up to now have not met a desired level in terms of efficiency, color purity, and lifetime characteristics.